So... currently it's 28 deg. F. (-2.2 c) outside. so obviously I can't put them up outside. (todays high is 41f, 5 c. So even if it cracks above freezing, it still won't be dry anytime today.) Historically, we would be at -20f, and would have been for the past month or two, and would be there for the next month, too. (you have no idea how freaky this winter has been here. 55 in jan/feb is... terrifying.)
I don't have the space to hang up bedding (top sheet, bottom sheet, comforter. pillow cases), 3 loads clothing, whatever loads my GF has, the towels, wash cloths, dishcloths and random other bits that need to be washed on a regular basis inside.
Honestly, for me personally this doesn't make any sense.
Firstly most fabric softeners are terrible for the moisture wicking abilities of fabrics. You should never use them on towels, bed sheets or any clothing that you expect to absorb sweat to some degree. They are known to contain chemicals that can pollute the ground water and they also cost money.
Now taking into account all that and the fact that using a dryer is very energy intensive, I find making all those comprimises just because you want your clothing to be soft is less than understandable.
I live in a 190sqft (18m²) single bedroom apt and I have the space for it. The amount of people that have even less space should be pretty low. At least the drying rack folds up and hides behind a cabinet. The dryer doesn't.
Pervasive mold is one of the drawbacks of living in my (beautifully forested and wet) part of the world. I can't line dry my cloths because stuff I'm allergic to will grow on it, rendering it unwearable.
How does the season or it being rainy or not change anything? I have been air drying my laundry all year round for the past eight years and I live in a pretty rainy climate.